1. Field of the Invention
The present invention relates to a zoom lens system and, more particularly, to a compact and low-price zoom lens system with favourable performance and high vari-focal ratio.
2. Description of the Prior Art
In recent years, zoom lens systems are becoming very popular and, as a result, there is a large demand for compact and low-price zoom lens systems. Zoom lens systems disclosed in Japanese published unexamined patent applications Nos. 161824/82 and 161804/82 are known as examples of zoom lens systems provided in order to fulfill the above-mentioned demand. In case of said zoom lens systems, the zoom ratio is large. However, the aperture ratio is small, i.e., F/5.6 in the teleposition, the overall length is long and, moreover, the number of lenses constituting the lens system is large, i.e., eleven lens components with fourteen lens elements.
In case of a zoom lens system disclosed in Japanese published examined patent application No. 9276/68, the lens system has nine-component eleven-element lens configuration. However, the fourth lens group thereof is arranged as a triplet type lens group and, therefore, the lens system cannot be made compact enough.